1. Field of the Invention
This invention relates generally to sights for archery bows employing fiber optic elements and, more specifically, to use of such fiber optic elements to provide various marking indicators for adjustment of the sight relative to a bow to which it is attached.
2. Description of the Art
Archery bow sights utilizing a plurality of sight pins have been known in the art for many years. Typically, these sights use a bracket or other mounting structure for mounting the sight to a bow. The sight is commonly comprised of a pin plate, a pin guard, and a plurality of sight pins which are secured to the pin plate and extend into a sight window formed by the pin guard. The sight is mounted to a bow in a manner so that when the bow string is drawn, the archer can look through a peep sight provided in the bow string and align the tip of a pin attached to the sight with a target. For sights utilizing a plurality of sight pins having their tips vertically aligned, each individual sight pin is typically provided for aiming the bow at a target at a particular distance from the archer. For example, one pin may be positioned in the sight for aiming the bow at a target 50 yards from the archer while another pin may be positioned for a target that is at 100 yards distance.
It is also known in the art to construct sight pins with a light-gathering fiber optic element to enable use of the sighting device in low light environments. Various configurations of sight pins using fiber optic members have been proposed. Fiber optic pins are typically formed from plastic under extreme pressure in a manner than causes the molecular chains within the plastic to align longitudinally with the fiber. When ambient light strikes the fiber optic material, it is absorbed and redirected along these molecular chains toward the ends of the fiber optic material. Thus, when the fiber optic material is exposed to light, the light essentially follows the path of least resistance and follows the molecular chains to the ends of the fiber optic member. As such, the ends of the fiber optic member appear to illuminate. Such plastic optical fibers are typically formed from either polycarbonate or polystyrene with the filaments of the fiber optic material shaped to fit different pin styles by heating and bending.
It is also well-known in the art that despite the light-gathering capabilities of fiber optic elements which render sighting devices more useful in low-light conditions (e.g., dusk), there is a point at which the ambient light is so low that the fiber optic element is no longer capable of gathering sufficient light to provide any illumination. While others in the art have disclosed the use of electronic means for providing a light source to the fiber optic elements of the sighting device, the use of such devices add weight to the device, may fail electrically and may be vulnerable to damage by contact with bushes or the like.
One particular type of sight known in the art uses a pivoting elevation system in which a single sight pin is adjusted up or down relative to the bow. The sight pin is adjusted to different vertical positions depending upon a particular distance-to-target. The pivoting mechanism is such that the sight pin is adjusted vertically without rotational or angular displacement through a lever and slide arrangement. The proximal end of the lever is provided with a laterally disposed needle that can be aligned with user provided markings (typically in the form of pencil or ink markings applied to a strip of adhesive backed paper) applied to the proximal end of the sight. Such method of marking does not lend itself to easy adjustment of the markings. In addition, the visibility of the needle and markings are significantly diminished in low light conditions.
Thus, it would be advantageous to use fiber optic elements to illuminate the markings and alignment of the sight using such fiber optic indicators in a bow sight that uses a pivoting elevation system for vertical adjustment of the sight pin.
It would also be advantageous to use a self-illuminating material, commonly referred to as glow-in-in-the-dark material to provide external illumination to the fiber optic elements in low light conditions.